Certain disease states require treatment using one or more different medicaments. Some drug compounds need to be delivered in a specific relationship with each other in order to deliver the optimum therapeutic dose. The presently proposed devices and methods are of particular benefit where combination therapy is desirable, but not possible in a single formulation for reasons such as, but not limited to, stability, compromised therapeutic performance and toxicology.
For example, in some cases it might be beneficial to treat a diabetic with a long acting insulin and with a glucagon-like peptide-1 (GLP-1), which is derived from the transcription product of the proglucagon gene. GLP-1 is found in the body and is secreted by the intestinal L cell as a gut hormone. GLP-1 possesses several physiological properties that make it (and its analogs) a subject of intensive investigation as a potential treatment of diabetes mellitus.
There are a number of potential problems when delivering two active medicaments or “agents” simultaneously. The two active agents may interact with each other during the long-term, shelf life storage of the formulation. Therefore, it is advantageous to store the active components separately and combine them at the point of delivery, e.g. injection, needle-less injection, pumps, or inhalation. However, the process for combining the two agents needs to be simple and convenient for the user to perform reliably, repeatedly and safely.
A further problem is that the quantities and/or proportions of each active agent making up the combination therapy may need to be varied for each user or at different stages of their therapy. For example one or more active agents may require a titration period to gradually introduce a patient up to a “maintenance” dose. A further example would be if one active agent requires a non-adjustable fixed dose while the other is varied in response to a patient's symptoms or physical condition. This problem means that pre-mixed formulations of multiple active agents may not be suitable as these pre-mixed formulations would have a fixed ratio of the active components, which could not be varied by the healthcare professional or user.
Additional problems arise where a multi-drug compound therapy is required, because many users cannot cope with having to use more that one drug delivery system or make the necessary accurate calculation of the required dose combination. This is especially true for users with dexterity or computational difficulties. In some circumstances it is also necessary to perform a priming procedure of the device and/or needle cannula before dispensing the medicaments.
For some drug combinations where a multi-drug compound therapy is required, it may be desirable to deliver medicament to two effectively separate depths within a single injection site. For instance, it may be desirable to deliver medicament to two effectively separate injection depths so that the two medicaments have minimal opportunity to mix in vivo. Currently, delivering medicament to two different injection site depths would necessitate two injections and potentially using two discrete injection devices.
Accordingly, there exists a need to provide devices and methods for the delivery of two or more medicaments to two effectively separate injection depths in a single injection or delivery step that is simple for the user to perform.
The presently proposed devices and methods overcome the above-mentioned problems by providing separate storage for two or more active drug agents that are then delivered to effectively separate injection depths in the patient during a single delivery procedure. Setting a dose of one medicament automatically fixes or determines the dose of the second medicament (i.e., non-user settable). The proposed devices and methods also give the opportunity for varying the quantity of one or both medicaments. For example, one fluid quantity can be varied by changing the properties of the injection device (e.g., dialing a user variable dose or changing the device's “fixed” dose). The second fluid quantity can be changed by manufacturing a variety of secondary drug containing packages with each variant containing a different volume and/or concentration of the second active agent. The user or healthcare professional would then select the most appropriate secondary package or series or combination of series of different packages for a particular treatment regime. The proposed medicated module includes a medicated needle cannula that holds a non-user-settable dose of medicament.
These and other advantages will become evident from the following more detailed description of the invention.